The subject matter described herein relates generally to electric power systems, and more specifically, to controlling operation of an auxiliary equipment system for a wind turbine.
Generally, a wind turbine includes a rotor that includes a rotatable hub assembly having multiple blades. The blades transform wind energy into a mechanical rotational torque that drives one or more generators via the rotor. At least some of the known wind turbines are physically nested together in a common geographical region to form a wind turbine farm. Variable speed operation of the wind turbine facilitates enhanced capture of energy as compared to energy capture during a constant speed operation of the wind turbine. However, variable speed operation of the wind turbine produces electric power with a varying voltage and/or frequency. More specifically, as is known, the frequency of the electric power generated by the variable speed wind turbine is proportional to the speed of rotation of the rotor. A power converter may be coupled between the wind turbine's electric generator and an electric utility grid. The power converter receives electric power from the wind turbine generator and transmits electricity with a fixed voltage and frequency to the utility grid via a transformer. Known transformers may be coupled to a plurality of power converters associated with the wind turbine farm.
Known wind turbines include auxiliary support equipment that facilitates operation of such wind turbines, for example, blade pitch drive motors, lubrication pump motors, and wind turbine control systems. Such auxiliary support equipment is powered by and receives at least a portion of electric power generated by the wind turbine generator or the electric utility grid. Moreover, such auxiliary support equipment typically has a predetermined voltage tolerance range. For example, at least some known support equipment may have a tolerance range that extends from 90% of nameplate voltage to 110% of nameplate voltage.
Many known electrical grids have voltage tolerance ranges that facilitate reliable electric power transmission and distribution over a wide variety of operational conditions to serve a broad market. For example, many known electrical grids include a grid voltage tolerance range that extends from less than 90% of nominally rated voltage to greater than 110% of nominally rated voltage. As such, many known wind turbines include auxiliary support equipment that is designed to operate within a voltage window that is not fully complimentary to the voltage window of the associated electrical grid. Exceeding the voltage tolerance ranges of the equipment may impair the operation of the equipment. Substituting, or replacing, such auxiliary support equipment with specialized equipment having broader electric power tolerances may be costly and may require an extended period of time that the wind turbine be removed from service.